Lecture 15 Thrush

Question 1

Difference between effector cells and naive cells

Answer 1

Naive: require CD:28- B7 for activation because it doesnt react wih TCR cells as well; CD45RA; low cell adhesion molecules (CD2 and LFA-1)

Effector cells: don’t require CD28:B7 for activation; high cell adhesion and use CD45RO

Question 2

CD4 T cells and subsets

Answer 2

Th (helper) cells produce cytokines to regulate the immune response (Th1 and Th2)
Tdth (delayed type hypersensitive) cells produce cytokines to stimulate an inflammatory response (Th1)
Tregs - regulatory/suppressive T cells; autoimmunity
Th17 - role in inflammation and autoimmunity
Th9 - promotes survival of Tregs
Th22 - helps control commensal bacteria, anti-inflammatory

Question 3

CD8 t cells subsets

Answer 3

Tc (cytotoxic) cells produce cytokines that kill target cells
Ts (suppressor) cells produce cytokines to turn off the immune response (?)

Question 4

CTLs: cell-mediated cytotoxic activities of the immune system and their role in host defense

Answer 4

important in eliminating altered self cells ( virally infected, tumor, and foreign graft)

best at destroying intracellular microbes

are CD8+ T cells that recognize their antigen in association with the MHC class I molecules.

Question 5

How do CTL-P become activated to become CTL?

Answer 5

TCR : Ag/MHC class I interaction (with CD8)
CD28 : B7
IL2R interaction with IL-2 (from Th1 cell)

Question 6

Which effector molecules do the CTLs produce

Answer 6

perforin: pore forming
granzymes: apoptosis and produces DNAses
Fas (on target cell) and FasL (on CTL): apoptosis

Question 7

Binding of Fas and TNF alpha causes?

Answer 7

direct killing of tumor cells

Question 8

NK: cell-mediated cytotoxic activities of the immune system and their role in host defense

Answer 8

No specific antigen recognition
Active before CTLS
Produces cytokines that can increase macrophages activity

produces perforin and granu.

Question 9

How do NK recognize target?

Answer 9

recgnize altered self cells

viruses, tumors

Question 10

What are the 2 NK receptors

Answer 10

KAR: activation
KIR: inhibtion

Question 11

What can serve as an inhibitory signal for NK?

Answer 11

MHC class 1

Question 12

What can bind to KAR?

Answer 12

cellular stress proteins, including MICA and MICB (are expressed by infected cells to help in actvating NK)

Question 13

NKT: cell-mediated cytotoxic activities of the immune system and their role in host defense

Answer 13

hybrid between T cells and NK cells
no memory cell
innate immunity
produces IFNg and IL-4 
recognize lipids when presented with CD1 molecules

Question 14

What type of TCRS do NKT cells have?

Answer 14

invariant; very limited diversity

Question 15

ADCC cell-mediated cytotoxic activities of the immune system and their role in host defense

Answer 15

antibodies

Question 16

where does the ADCC antibody and antigen bind?

Answer 16

Fc region

Question 17

which cells express FcR

Answer 17

Nk cells, neutrophils, macrophages, eosinophils,

Question 18

how do ADCC cause cell death?

Answer 18

by releasing granules

can release TNF which can relases perforins and gran.

Question 19

What can stimulate ADCC?

Answer 19

IgE